Bondo® Liquid Resin for Fiberglass

  • 3M ID B40068242
  • UPC 00076308004040

SEAL CRACKS, REPAIR BREAKS, and recreate or join surfaces for auto, boat, and home applications

INTERIOR OR EXTERIOR use

DESIGNED TO USE on fiberglass, metal, wood, and masonry surfaces

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Highlights
  • SEAL CRACKS, REPAIR BREAKS, and recreate or join surfaces for auto, boat, and home applications
  • INTERIOR OR EXTERIOR use
  • DESIGNED TO USE on fiberglass, metal, wood, and masonry surfaces
  • USE WITH BONDO® Fiberglass Cloth or Mat for larger repairs and long-term strength
  • 100% WATERPROOF creates strong, durable seal for concrete, showers, boats, and more
  • TWO-PART FORMULA creates extremely strong chemical bond to surfaces
  • SANDABLE in 2 hours
  • PAINTABLE FORMULA is compatible with most paints and gel coats
  • BONDO® CLEAR LIQUID Hardener included
  • MIXES TRANSLUCENT LIGHT BROWN when liquid hardener drops and resin are mixed thoroughly and ready to use
  • WORKABLE for 8-12 minutes once resin and hardener drops are mixed together
  • FILL STAGE of 3M™ Body Repair System

Bondo® Liquid Resin for Fiberglass is a high-strength polyester resin that can be used with fiberglass mats or cloths on surfaces including fiberglass, metal, wood, and masonry. This all-purpose material is used to repair breaks, and recreate or join surfaces. It can also be used by itself as a wood or concrete sealer. The 100% waterproof, two-part resin includes clear liquid hardener and can be used to repair cars, trucks, pools, showers, boats and more.

Bondo® Liquid Resin for Fiberglass Filler instructions:
Step 1: For repairing cracks in fiberglass: Sand in and around the damaged area with 80 grit sandpaper, removing any gel coat, paint, primer, and debris. Clean again with a low VOC compliant cleaner and allow to dry.
For repairing damaged fiberglass and metal areas with holes and gaps, fiberglass cloth or mat is needed to reinforce the repair: Cut away the damaged area and any loose pieces. Sand the repair area to remove all primer, paint, rust, or gel-coat using 80 grit sandpaper or a 40 grit sanding disc. Sand 2 to 3 inches beyond the repair area down to bare metal or fiberglass. Clean again with a low VOC compliant cleaner.
For use as a concrete or wood sealer to seal small areas: Clean the surface to make it free of dust and debris.
For any other surface: Clean all surfaces to be repaired, or sealed, with soap and water followed by a low VOC compliant cleaner. Allow to dry.

Step 2: Remove the cap from the liquid hardener tube and using a push pin, press a hole into the dispensing end of the tube.

Step 3: Estimate the amount of resin needed to complete the repair. The working time of mixed resin is 8 to 12 minutes at 75 °F (24 °C), so only mix it in small amounts that can be used within that time. Mix 1 ounce of resin with 10 drops of hardener; if more resin is needed see the list below to estimate the amount of hardener. Use a clean, wax-free mixing cup and scrape the sides of the cup to ensure complete mixing while stirring gently for 30 to 45 seconds. Do not mix hardener directly into the resin can.

Depending on the amount of liquid resin needed, mix with the right amount of hardener:
For every ounce of resin, add 10 drops of hardener.
For a ¼ of the 0.9 Pint can, add ¼ of a 0.37 oz tube of hardener.
For a ¼ of the 0.9 Quart can, add a ¼ of a 0.74 oz tube of hardener.
For a ¼ of the 0.9 Gallon can, add ½ of a 0.74 oz tube of hardener.

Step 4: For repairing cracks in fiberglass: Using a paint brush, apply Bondo® Liquid Resin for Fiberglass into the crack and surrounding area, clamping the cracked area together as needed. Allow resin to cure.
For repairing damaged fiberglass and metal areas with holes and gaps, fiberglass cloth or mat is needed to reinforce the repair: Pre-cut several pieces of Bondo® Fiberglass Cloth or Mat, sold separately but is included in kit, to extend 2 to 3 inches beyond the repair area. Using a paint brush, apply a coat of the mixed resin on the repair area extending 2-3 inches beyond the repair. Place the first layer of fiberglass cloth or mat onto the mixed resin to tack it in place. Now brush additional mixed resin into the cloth or mat. A dabbing motion will help ensure that the cloth is saturated with resin and may help remove any air pockets. Continue applying additional layers of fiberglass cloth or mat and mixed resin, as needed, while the first layer is still sticky or wet. If the surface has dried hard and is no longer sticky, sand with 80 grit sandpaper before applying additional layers of mixed resin and fiberglass cloth or mat. Follow the same procedure if both sides are being repaired.
For use as a concrete or wood sealer for small areas: Brush or roll the resin onto the surface until saturation to create a water-tight finish. Note that the product will be slippery after curing; do not use on walking surfaces.
For repairing pinholes or waterproofing a surface: Using a paint brush, apply Bondo® Liquid Resin for Fiberglass onto the surface until saturation to create a water-tight finish.

Step 5: Material cures in approximately 2 hours at 75°F. Curing will take longer in cooler temperatures. To speed curing time, a heat lamp may be used 18” from the repair area for 15 minutes. CRACKING CAN OCCUR IF OVERHEATED.

Step 6: Smooth the repair area using 180 grit sandpaper and featheredge to blend it into surrounding surfaces. The repair is now ready for primer, paint, or gel coat. Follow paint manufacturer’s recommendation for priming and final finishing.

Step 7: Cleanup: while the mixed resin is still wet, clean paint brush and tools with acetone or lacquer thinner.

DO NOT POUR MIXED RESIN BACK INTO THE CAN as it will harden the rest of the contents. Store the hardener tube under the plastic resin container cap. 

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